Topical compositions and methods for skin lightening

ABSTRACT

Embodiments of the invention are generally directed to compositions useful for reducing pigmentation in the skin. The composition may further include other depigmenting agents such as nicotinamide and its melanasome transfer-inhibiting derivatives, 3,3′-thiodipropanoic acid and its tyrosinase-inhibiting derivatives, or resorcinol and its tyrosinase-inhibiting derivatives, in a topically acceptable vehicle.

FIELD OF INVENTION

The invention relates generally to cosmetic and dermatologicalcompositions and methods for reducing pigmentation in human integuments.More particularly, the invention provides topical compositions andassociated methods for treatment of hyperpigmentation or reduction ofunwanted pigmentation. The compositions may be applied topically to skinto reduce pigmentation in the area of application.

BACKGROUND

The color of human skin is due primarily to the production of melanin byspecialized cells in the skin called melanocytes through a process knownas melanogenesis. The synthesis of melanin is a complex processinvolving several biochemical pathways. It is generally recognized thatpigmentation may accompany inflammatory processes. Histamine is an agentinvolved in the inflammatory response which is reported to increasetyrosinase activity in human melanocytes, with the effects beingcompletely inhibited by histamine antagonists such as famotidine.Histamine is postulated to induce melanogenesis in human culturedmelanocytes by protein kinase A activation via H₂ receptor. See Yoshida,M. et al., Journal of Investigative Dermatology (2000) 114, 334-342, thecontents of which are incorporated by reference herein. Recently, theexpression of histamine receptors on melanocyte cells has been reported.See Salim, S. et al., J Recept Signal Transduct Res. 2011 April;31(2):121-31, the contents of which are incorporated by referenceherein. However, the use of histamine antagonists to reduce pigmentationhas received little attention to date.

Known depigmenting agents, such as hydroquinone and kojic acid, act asinhibitors of tyrosinase, an enzyme that has its catalytically activedomain within organelles known as melanosomes. Tyrosinase convertsphenols, including tyrosine, to ortho-quinones which are subsequentlyconverted to melanin within the melanosomes. Other skin lighteners, suchas plasminogen-activated receptor, act by disrupting the transfer of themelanosomes from melanocytes to the keratinocytes where melanin isdeposited. While skin lighteners such as hydroquinone and kojic acidhave found some utility in cosmetic and dermatological products, thereremains a continuing need for products that effectively reducepigmentation of skin particularly through mechanisms that may becomplementary to those mentioned above to promote enhanced efficacyand/or synergies of combinations of depigmenting agents. It is thereforean object of the invention to provide compositions and methods forreducing pigmentation in human skin, including, for example, treatmentof hyperpigmentation, unwanted pigmentation, age spots, liver spots,freckles, and the like.

The foregoing discussion is presented solely to provide a betterunderstanding of nature of the problems confronting the art and shouldnot be construed in any way as an admission as to prior art nor shouldthe citation of any reference herein be construed as an admission thatsuch reference constitutes “prior art” to the instant application.

SUMMARY OF DISCLOSURE

In accordance with the foregoing objectives and others, the inventionprovides compounds, topical compositions and methods for reducingpigmentation in human skin. Without wishing to be bound by any theory,it is believed that the compounds of the invention are histaminereceptor (e.g., H₁, H₂, H₃ and/or H₄ receptor) antagonists effective toreduce histamine-induced pigmentation in human skin. In someimplementations, new H₂ receptor antagonists are provided. Thecompositions and methods may treat hyperpigmentation conditions,including those associated with UV damage, inflammation, andchronological aging, including without limitation treating,ameliorating, diminishing the appearance of, or preventing age spots,liver spots, freckles, mottled and discrete pigmentation, melasma andthe like. The compositions and methods are also useful for reducingotherwise unwanted pigmentation, including overall lightening of theskin, as well as improving signs of chronological, environmental, or UVskin aging.

Various non-limiting embodiments of the invention are described below.It will be understood that throughout these embodiments, the term“reducing pigmentation” includes reducing, lessening, or diminishing theappearance of hyperpigmentation, including freckles, sun spots, agespots, etc., as well as lightening skin that may or may not be affectedby hyperpigmentation. Reference to human skin in each of theseembodiments, includes without limitation, skin of the face, neck, arms,hands, legs, etc.

The compounds of the invention have been found to be human histaminereceptor antagonists (in particular, at the H₂ receptor) and thus areexpected to reduce pigmentation, including histamine-inducedpigmentation of human integuments such as skin. In some embodiments, thecompounds are histamine H₂ receptor antagonists, although it iscontemplated that the compounds may act on any of H₁, H₂, H₃, or H₄receptors or have non-specific activity (e.g., antagonist activity)across two or more of these receptors. However, it will be understoodthat the precise mechanism of action of the compounds is not intended tolimit the invention unless otherwise indicated. The compounds of theinvention are contemplated to be beneficial in reducing pigmentationand/or treating hyperpigmentation regardless of the mode of action.

In one aspect of the invention, topical compositions are provided forreducing pigmentation of human integuments (e.g., skin) comprising, in atopically acceptable vehicle (e.g., a water-in-oil, or oil-in-wateremulsion or an aqueous serum), an effective amount (e.g., from about0.0001% to about 0.01%, or to about 0.1%, or to about 1%, or to about10% by weight) of a compound (e.g., an H₂ antagonist compound) accordingto formula (I):

In the compound of formula (I), R^(N) may be independently selected ateach occurrence (i.e., they may be the same or different from oneanother) from hydrogen or saturated or unsaturated C₁₋C₁₂ hydrocarbons,including, without limitation saturated or unsaturated aliphatic C₁₋C₁₂hydrocarbons (e.g., C₁-C₄ alkyl such as methyl, ethyl, propyl, butyl,etc.); aromatic C₁-C₁₂ hydrocarbons (e.g., phenyl, tolyl, etc.);aliphatic C₁-C₁₂ heterocycles, aromatic C₁-C₁₂ heterocycles, orcombinations thereof (e.g, alkyl-aryl groups including benzyl); each ofthe foregoing optionally containing from 1-8 (or 1-3) heteroatomsselected from halogen, O, N, and S, and wherein any two groups R^(N) maytogether form a three- to six-membered ring (e.g., piperidine,morpholine, piperazine, etc.). In one embodiment, two groups R^(N)together with the nitrogen atom from a piperidine ring.

R^(a) may be selected from hydrogen, —F; —Cl; —Br; —I; —OH, —OR*; —NH₂;—NHR*; —N(R*)₂; —N(R*)₃*; —N(R*)—OH; —N(→O)(R*)₂; —O—N(R*)₂;—N(R*)—O—R*; —N(R*)—N(R*)₂; —C═N—R*; —N═C(R*)₂; —C═N—N(R*)₂;—C(═NR*)—N(R*)₂; —SH; —SR*; —CN; —NC; —(C═O)—R*; —CHO; —CO₂H; —CO₂—;—CO₂R*; —(C═O)—S—R*; —O—(C═O)—H; —O—(C═O)—R*; —S—(C═O)—R*; —(C═O)—NH₂;—(C═O)—N(R*)₂; —(C═O)—NHNH₂; —O—(C═O)—NHNH₂; —(C═S)—NH₂; —(C═S)—N(R*)₂;—N(R*)—CHO; —N(R*)—(C═O)—R*; —(C═NR)—O—R*; —O—(C═NR*)—R*, —SCN; —NCS;—NSO; —SSR*; —N(R*)—C(═O)—N(R*)₂; —N(R*)—C(═S)—N(R*)₂; —SO₂—R*;—O—S(═O)₂—R*; —S(═O)₂—OR*; —N(R*)—SO₂—R*; —SO₂—N(R*)₂; —O—SO₃—;—O—S(═O)₂—OR*; —O—S(═O)—OR*; —O—S(═O)—R*; —S(═O)—OR*; —S(═O)—R*; —NO;—NO₂; —NO₃; —O—NO; —O—NO₂; —N₃; —N₂—R*; —N(C₂H₄); —Si(R*)₃; —CF₃;—O—CF₃; —PR*₂; —O—P(═O)(OR*)₂; —P(═O)(OR*)₂; C₁-C₈ perfluoroalkyl; analiphatic C₁-C₈ hydrocarbon radical; a C₁-C₈ aromatic hydrocarbonradical; or a C₁-C₈ heteroaryl radical. The phenyl rings to which R^(a)is attached may comprise from 0-4 (or 0, 1, 2, 3, or 4) groups R^(a),which will be independently selected at each occurrence.

X₁ and X₂ are independently selected from oxygen, sulfur, NR*, or CR*R*(typically, X₁ and/or X₂ is NH).

R* is independently, at each occurrence, hydrogen or a straight chained,branched, or cyclic C₁₋₂₀ (e.g., C₁₋₁₀ or C₁₋₆, or C₁₋₄, or C₁₋₃)hydrocarbon radical, which may be saturated, partially unsaturated, oraromatic, each of which may be optionally substituted with 1-6 (e.g.,1-4 or 1-3) heteroatoms selected from nitrogen, oxygen, sulfur, orhalogen, including, without limitation, methyl, ethyl, propyl, butyl,etc.

Ring “A” is a five or six-membered optionally aromatic ring, z₁ is —C—,—N—, —NL₁-, or —CL₁-; and z₂-z₆ are independently selected from —N—,—NH—, —NR*—, —NL₁-, —O—, —S—, —CH—, —CR—, —CR*—, and in the case wherering “A” is a five membered ring, z₄ is a bond (i.e., it is absent); andwhere L₁ is a linking moiety that forms a linkage between ring A and thechain, where L₁ is group—X^(a)—(CH₂)_(r)—(CH═CH)_(s)—X^(b)—(CH₂)_(y)—(CH═CH)_(z)—X^(c)—, whereX^(a), X^(b), and X^(c) are independently a bond (i.e., absent), —O—,—S—, —NH—, —NR*— and “r,” “s,” “y,” and “z” are independently at eachoccurrence integers from 0-2.

Ω is selected from H, R*, OH, OR*, or NR^(N)R^(N), wherein R^(N) and R*are as defined above. Ω may be, for example, a group R* includingwithout limitation lower alkyl (e.g., methyl, ethyl, propyl, butyl,pentyl and hexyl), phenyl, benzyl, each of which may include from 0-4heteroatoms selected from O, N, S, and halogen, or may include a groupR^(a).

n and m are independently integers from 0-6, (e.g., 1-3) and in someembodiments n and m are each 1.

In another implementation, topical compositions are provided comprising,in a topically acceptable vehicle (e.g., an emulsion or serum), aneffective amount (e.g., from about 0.0001% to about 0.01%, or to about0.1%, or to about 1%, or to about 10% by weight) of a compound (e.g., anH₂ antagonist compound) having the structure of formula (II):

Topically acceptable salts (e.g., acid addition salts) of the compoundsof formulas (I) or (II) are also suitable. The compositions of theinvention typically comprise a vehicle, for example a water-in-oil oroil-in-water emulsion, which may further include various adjuvants suchas thickeners, emulsifiers, gellants, emollients, humectants, UVabsorbers, antioxidants, pH adjusters, chelators, film formers,preservatives, colorants, fragrances, and the like. The adjuvants maycomprise, individually or collectively, from about 0.00001% to about 98%by weight of the composition. The topical preparations of the inventionmay further include one or more additional active agents, such as aretinoid (e.g., retinol, retinyl palmitate, retinyl acetate,retinaldehyde, retinoic acid, etc.), and antioxidant (e.g., ascorbicacid, thiodipropionic acid or esters thereof, including dilaurylthiodipropionate), α-hydroxy acids (e.g., glycolic acid), collagenaseinhibitors, anti-inflammatories, anti-acne agents, salicylic acid andderivatives, depigmenting agents, N-acetyl tyrosinamide, and botanicals,to name a few. In some embodiments, the compounds of formula (I) or (II)are provided in combination with at least one additional depigmentingagent, such as a tyrosinase inhibitor or a melanosome transferinhibitor. In one embodiment, the compositions include one or more ofhydroquinone, kojic acid, salicylic acid or derivatives, thiodipropionicacid, and retinoids. Additional actives may individually or collectivelycomprise from about 0.0001% to about 20% by weight of the composition.

Topical compositions comprising a compound of formula (I) or (II) may beapplied for a time sufficient to achieve a reduction in pigmentation inthe area of application (e.g., application at least once or twice dailyfor at least one week, at least two weeks, at least four weeks, or atleast eight weeks or longer. In some embodiments, the compositions areapplied daily to achieve and/or maintain a reduction in pigmentation inthe skin.

In one aspect of the invention, a method for reducing pigmentation inhuman skin is provided comprising topically applying the compound offormula (I) or (II) to skin. Without wishing to be bound by anyparticular theory, it is believed that the compounds of formula (I) or(II) act as histamine receptor (e.g., H₂ receptor) antagonists i.e.,block or dampen histamine-mediated responses, which results insuppression of post-inflammation induced melanogenesis and production ofmelanin in the skin, thus reducing or diminishing pigmentation thereof.

These and other aspects of the present invention will be betterunderstood by reference to the following detailed description andappended claims.

DETAILED DESCRIPTION

Detailed embodiments of the present invention are disclosed herein;however, it is to be understood that the disclosed embodiments aremerely illustrative of the invention that may be embodied in variousforms. In addition, each of the examples given in connection with thevarious embodiments of the invention is intended to be illustrative, andnot restrictive. Therefore, specific structural and functional detailsdisclosed herein are not to be interpreted as limiting, but merely as arepresentative basis for teaching one skilled in the art to variouslyemploy the present invention.

All percentages given herein refer to the weight percentages of aparticular component relative to the entire composition, including thevehicle, unless otherwise indicated. It will be understood that the sumof all weight % of individual components within a composition will notexceed 100%.

All terms used herein are intended to have their ordinary meaning unlessotherwise provided. The phrases “cosmetically acceptable,” “topicallyacceptable” and “dermatologically acceptable” are used interchangeablyand are intended to mean that a particular component is generallyregarding as safe and non-toxic for application to a human integument(e.g., skin) at the levels employed. The term “prevent,” as used herein,includes delaying the onset of or progression of a particular sign ofskin aging. The phrase “individual in need thereof” refers to a humanthat could benefit from improved dermal appearance or health, includingmales or females. In some embodiments, the individual in need thereof isa female. The term “skin” includes, without limitation, the lips, skinof the face, hands, arms, neck, scalp, and chest. As used herein, theterm “consisting essentially of” is intended to limit the invention tothe specified materials or steps and those that do not materially affectthe basic and novel characteristics of the claimed invention, asunderstood from a reading of this specification.

The compositions may be used for reducing pigmentation and/or lighteningareas of the human integumentary system, including but not limited to,keratinous surfaces such as skin, hair, lips, and nails. Thecompositions are typically topical compositions that once applied to theintegumentary system result in a lightening (e.g., de-pigmenting) of theintegument to which it is applied.

In some embodiments, the compositions and methods are for the treatmentof hyperpigmentation, which includes eradicating, reducing,ameliorating, or reversing a degree of subject pigmentation. Thehyper-pigmentation may result from increased presence of one or more ofthe different types of melanin biosynthesized in skin and/or folliclesand deposited in hair or skin, relative to a subject's baselinepigmentation. The compositions may be applied directly to a localizedsite of hyper-pigmentation.

In some embodiments, the compositions and methods are for lighteningskin, which includes eradicating, reducing, ameliorating, and/orreversing a baseline degree of subject pigmentation. Lightening skin maybe measured by observing changes in Fitzpatrick scale value of asubject. The Fitzpatrick Scale (aka, Fitzpatrick skin typing test orFitzpatrick phototyping scale) is a numerical classification schema forthe color of skin, and remains a recognized tool for dermatologicresearch into the color of skin. The Fitzpatrick Scale measures severalcomponents, including Genetic Disposition, Reaction to Sun Exposure andTanning Habits, and classifies skin into six types: Type I (scores 0-7)refers to white, very fair skin, freckles, typical albino skin, thatalways burns, never tans; Type II (scores 8-16) refers to white, fairskin, that usually burns, or tans with difficulty; Type III (scores17-24) refers to beige, which is very common, and which sometimessuffers mild burn, gradually tans to a light brown; Type IV (scores25-30) refers to beige skin with a brown tint, which is typical ofMediterranean Caucasian skin, and which rarely burns, tans with ease toa moderate brown; Type V (scores over 30) refers to dark brown skinwhich very rarely burns, tans very easily; Type VI refers to black skinthat never burns, tans very easily, and is deeply pigmented. In someembodiments of the invention, the treatments are capable of changing thetreated area of skin by at least one or at least two skin type on theFitzpatrick scale. When lightening skin, it may be desirable to applythe composition over a large area of skin (e.g., over the entire skin ofthe face).

The compositions and methods of the invention are also contemplated tobe useful for treating, reducing, ameliorating, improving, alleviating,and/or eliminating the dermatological effects of aging and/orenvironmental stress. The compositions and methods are suitable for usein treating dermatological conditions of the skin (including excessiveor unwanted pigmentation) in numerous areas of the body, including,without limitation, the face, forehead, lips, neck, arms, hands, legs,knees, feet, chest, back, groin, buttocks, thighs, and the like. In oneembodiment, the compositions are applied to the face, chest, arms and/orhands.

Specific benefits which may be achieved include, but are not limited to,reducing pigmentation of dark or hyperpigmented skin, reducing age spotsor liver spots; reducing pigmented birthmarks, sun damage, tans,pigmented acne marks, scars; evening out or optimizing skindiscoloration; decreasing the appearance of dark circles under the eyes;treating melasma, cholasma, freckles, after-burn scars, yellowing ofskin, and post-inflammation and post-injury hyperpigmentation;lightening hair on the scalp, legs, face, and other areas wherewhitening and color reduction are desired; and removing or reducing nailstains.

The compounds, compositions and methods of use thereof are not limitedby any particular characterization of the physiological and/or chemicaleffects of lightening agents. Various skin lightening pathways are knownand include, for example, those that occur by decreasing melanogenesisby decreasing tyrosinase activity in melanocytes as well as inhibitingmelanosome maturation. However, the lightening agents used in thepresent compositions and methods are believed to lighten skin by actingas histamine receptor (e.g., H₁ and/or H₂) antagonists, i.e., blockingor dampening histamine-mediated responses, which results in suppressionof post-inflammation induced melanogenesis and production of melanin inthe skin, thus reducing or diminishing pigmentation thereof.

The compounds of the invention (e.g., H₂ receptor antagonist compounds)may have the structure of formula (I):

R^(N) may be independently selected at each occurrence from hydrogen orC₁-C₁₂ hydrocarbons. The C₁₋C₁₂ hydrocarbons include, withoutlimitation, saturated or unsaturated aliphatic C₁₋C₁₂ hydrocarbons(e.g., alkyl groups such as methyl, ethyl, propyl, butyl, etc.);aromatic C₁-C₁₂ hydrocarbons (e.g., phenyl, tolyl, etc.); aliphaticC₁-C₁₂ heterocycles, aromatic C₁-C₁₂ heterocycles, or combinationsthereof. In some embodiments, the C₁₋C₁₂ hydrocarbons are C₁₋C₁₂ alkyl,or C₂₋C₁₂ alkenyl, or C₂₋C₁₂ alkynyl or C₆₋C₁₂ aryl, or C₆₋C₁₂alkyl-aryl or aryl-alkyl groups. The C₁₋C₁₂ hydrocarbons optionallycontain from 1-8 (or 1-4, or 1-3) heteroatoms selected from halogen(e.g., F, Cl, Br, etc.), O, N, and S (including combinations thereof).In some embodiments, two groups R^(N) on the same nitrogen atom maytogether form a three- to six-membered ring (e.g., 3, 4, 5, or 6members) including the nitrogen atom.

R^(a) may be located on any available position on the ring to which theyare attached and may be present on 0-4 of the available positions andindependently selected at each occurrence. R^(a) may be independentlyselected at each occurrence from hydrogen, —F; —Cl; —Br; —I; —OH, —OR*;—NH₂; —NHR*; —N(R*)₂; —N(R*)₃; —N(R*)—OH; —N(→O)(R*)₂; —O—N(R*)₂;—N(R*)—O—R*; —N(R*)—N(R*)₂; —C═N—R*; —N═C(R*)₂; —C═N—N(R*)₂;—C(═NR*)—N(R*)₂; —SH; —SR*; —CN; —NC; —(C—═O)—R*; —CHO; —CO₂H; —CO₂—;—CO₂R*; —(C═O)—S—R*; —O—(C═O)—H; —O—(C═O)—R*; —S—(C═O)—R*; —(C═O)—NH₂;—(C═O)—N(R*)₂; —(C═O)—NHNH₂; —O—(C═O)—NHNH₂; —(C═S)—NH₂; —(C═S)—N(R*)₂;—N(R*)—CHO; —N(R*)—(C═O)—R*; —(C═NR)—O—R*; —O—(C═NR*)—R*, —SCN; —NCS;—NSO; —SSR*; —N(R*)—C(═O)—N(R*)₂; —N(R*)—C(═S)—N(R*)₂; —SO₂—R*;—O—S(═O)₂—R*; —S(═O)₂—OR*; —N(R*)—SO₂—R*; —SO₂—N(R*)₂; —O—SO₃—;—O—S(═O)₂—OR*; —O—S(═O)—OR*; —O—S(═O)—R*; —S(═O)—OR*; —S(═O)—R*; —NO;—NO₂; —NO₃; —O—NO; —O—NO₂; —N₃; —N₂—R*; —N(C₂H₄); —Si(R*)₃; —CF₃;—O—CF₃; —PR*₂; —O—P(═O)(OR*)₂; —P(═O)(OR*)₂; C₁-C₈ perfluoroalkyl; analiphatic C₁-C₈ hydrocarbon radical; a C₁-C₈ aromatic hydrocarbonradical; or a C₁-C₈ heteroaryl radical. In some embodiments R^(a) willbe present at 0, 1, 2, 3, or 4 different positions on the ring.

X₁ and X₂ are independently selected from oxygen, sulfur, NR*, or CR*R*,but typically, X₁ and/or X₂ is NH or NR*.

R* is independently at each occurrence selected from hydrogen or astraight chained, branched, or cyclic C₁₋₂₀ (e.g., C₁₋₁₂ or C₁₋₆, orC₁₋₄, or C₁₋₃) hydrocarbon radical, which may be saturated, partiallyunsaturated (e.g., one, two, or three double or triple bonds), oraromatic (e.g., heteroaromatic), each of which may be optionallysubstituted with 1-6 (e g., 1-4 or 1-3) heteroatoms selected fromnitrogen, oxygen, sulfur, or halogen. Examples of R* include C₁₋C₁₂, orC₁₋C₆, or C₁₋C₄ alkyl, including methyl, ethyl, propyl (e.g., n-propylor iso-propyl), butyl, pentyl, hexyl, etc.; C₆₋C₁₂ aryl groups includingphenyl; C₇₋C₁₂ aryl-alkyl or alkyl-aryl groups like benzyl, tolyl, etc.

Ring “A” is a five or six-membered optionally aromatic ring, z₁ is —C—,—N—, —NL₁-, or —CL₁-; and z₂-z₆ are independently selected from —N—,—NH—, —NR*—, —O—, —S—, —CH—, —CR—, —CR*—, and in the case where ring “A”is a five membered ring, z₄ is a bond (i.e., it is absent); and where L₁is group—X^(a)—(CH₂)_(r)—(CH═CH)_(s)—X^(b)—(CH₂)_(y)—(CH═CH)_(z)—X^(c)—, whereX^(a), X^(b), and X^(c) are independently a bond (i.e., absent), —O—,—S—, —NH—, —NR*— and “r,” “s,” “y,” and “z” are independently at eachoccurrence integers from 0-2.

Ω is selected from H, R*, OH, OR*, or NR^(N)R^(N), wherein R^(N) and R*are as defined above.

n and m are independently integers from 0-6, (e.g., 1-3). Typically oneor more (and sometimes all) of n and m are 1.

In certain implementations, R^(a) may independently be selected, at eachoccurrence, from hydrogen, methyl, ethyl, propyl, butyl, pentyl, andhexyl. In certain implementations, R^(a) is a hydrogen at alloccurrences. In some embodiments, R* is present at one, two, three orfour positions on the ring to which it is attached.

In certain implementations, two groups R^(N) located on the samenitrogen atom may form a ring together with the nitrogen atom to whichthey are attached. In one embodiment, two groups R^(N) form asix-membered ring. The six-membered ring may be, for example,piperidine, morpholine, thiomorpholine, piperazine, etc. In anotherembodiment, two groups R^(N) form a five-membered ring together with thenitrogen atom to which they are attached. The five membered rings maybe, for example, pyrrole, pyrrolidine, imidazolidine, oxazolidine,thiazolidine, etc. In another embodiment two groups R^(N) are hydrogens.

In certain implementations, n and m are independently integers from 0-5.In one embodiment, n and m are independently integers from 1-4. Inanother embodiment, n and m are independently integers from 1-2. Inanother embodiment, n and/or m are 1.

In certain implementations, Ω may be selected from methyl, ethyl,propyl, butyl, pentyl, and hexyl. In certain implementations, Ω ismethyl.

In one embodiment, wherein z₄ is a bond (i.e., it is absent), ring “A”may be selected from the group consisting of:

wherein ε₁, ε₂, and ε₃, are independently selected from N, NH, NR*, S,and O; with the proviso that where the point of attachment is ε₁, ε₂, orε₃, then that position represents N; and wherein carbon atoms which arenot the point of attachment may be optionally substituted with a groupR*; and wherein the dashed circles indicate that each ring may comprisezero, one, or two double bonds. In some embodiments, ring “A” is a ringQ having the form:

wherein any available site on the ring “A” or “Q” may be optionallysubstituted with a group R (e.g., methyl, methoxy, halo, hydroxyl,amino, etc.). In some embodiments, ring “A” is:

In another embodiment, ring “A” is a six membered aromatic ring.

In another implementation, topical compositions are provided comprisinga compound having the structure of formula (II):

Topically acceptable salts of the compounds of formulas (I) or (II) arealso suitable. Salts will typically be acid addition salts formed by thereaction of a compound of formulas (I) or (II) with an inorganic or anorganic acid. Inorganic acids include mineral acids such as HCl andH₂SO₄, and the like.

The compositions according to the invention can be formulated in avariety of forms for topical application and will typically comprisefrom about 0.000001% by weight to about 20% by weight of one or morecompounds according to Formula (I) or (II), and preferably will comprisefrom about 0.00001% by weight to about 10% by weight, and morepreferably from about 0.0001% by weight to about 5% by weight of thecomposition. In one embodiment, the active will comprise from about0.0001% by weight to about 0.1% by weight or to about 0.5% by weight orto about 1% by weight of the composition. The compositions will compriseand effective amount of the compound according to Formula (I) or (II),by which is meant an amount sufficient to have amelanogenesis-suppressive effect in a given area of skin when topicallyapplied thereto.

It may be advantageous to employ the compound of formulas (I) or (II)together (including simultaneous or serial application) with other skinlightening agents such as tyrosinase inhibitors and/or melanosometransfer inhibitors. Special mention may be made of hydroquinone and themonobenzyl ether thereof; hydroquinone-beta-D-glucopyranoside; retinoids(e.g., retinol or retinoic acid); tretinoin; nicotinamide, niacinamide,hydroxystilbenes, flavonoids, resveratrol, oxyresveratrol,piceid-glucoside, rhapontigenin, rhaponticin, azelaic acid; Kojic acid(5-hydroxy-4-pyran-4-one-2-methyl); melatonin, Mequinol(4-hydroxyanisole); soy protein (e.g., Bowman Birk inhibitor (BBI)and/or soybean trypsin inhibitor (STI)) and other serine proteaseinhibitors; paper mulberry extract; Glutathione, glycolic acid,Glabridin (licorice extract); Arctostaphylos patula and Arctostaphylosviscida extracts; gentisic acid, Glycyrrhiza glabra and its derivatives;Chlorella vulgaris extract; Magnesium-L-ascorbyl-2-phosphate (MAP);4-Isopropylcatechol; Arbutin; Aleosin; Linoleic acid;N-acetyl-4-S-cysteaminylphenol and N-propionyl-4-S-cysteaminylphenol;N-acetyl glucosamine; and Tranexamic acid(trans-4-aminomethylcyclohexanecarboxylic acid); bearberry extract,ascorbic acid and/or its derivatives, salicylic acid and derivatives,perilla extract (e.g., in U.S. Pat. No. 5,980,904 and JapanesePublications Nos. 07025742, 07187989, 10265322, 2001163759, and2001181173, incorporated herein by reference), coconut fruit extract(Japanese Patent No. 2896815B2, incorporated by reference herein),coconut water, green tea extract, ginseng, gingko, gallic acid,α-tocospherol and calcium influx inhibitors, to name a few. Any of thetyrosine inhibitors disclosed in KR 2005095167; JP 2003252743; and JP61260009, incorporated by reference herein, may be included, in someembodiments. In another embodiment of the invention, the compositionsmay include any of the following ingredients, alone or in combination:nilopala; patanga; chandana; ushira; manjshta; kumkuma; laksa;padmakesara; padmaka; yashtimadhu; ajakshira; ksheera; nyagrodhapada;and/or lodhra. These additional depigmenting agents may individually orcollectively comprise from about 0.0001% or about 0.01% to about 10% orabout 20% by weight of the composition.

The cosmetically acceptable vehicle may be in the form of an emulsion.Non-limiting examples of suitable emulsions include water-in-oilemulsions, oil-in-water emulsions, silicone-in-water emulsions,water-in-silicone emulsions, wax-in-water emulsions, water-oil-watertriple emulsions or the like having the appearance of a cream, gel ormicroemulsions. As used herein, the term “oil” includes silicone oilsunless otherwise indicated. The emulsion may include an emulsifier, suchas a nonionic, anionic or amphoteric surfactant, or a gallant, typicallyin an amount from about 0.001% to about 5% by weight.

The cosmetically acceptable vehicle may include water; vegetable oils;mineral oils; ester oils such as octal palmitate, isopropyl myristateand isopropyl palmitate; ethers such as dicapryl ether and dimethylisosorbide; alcohols such as ethanol and isopropanol; fatty alcoholssuch as cetyl alcohol, cetearyl alcohol, stearyl alcohol and behenylalcohol; isoparaffins such as isooctane, isododecane (IDD) andisohexadecane; silicone oils such as cyclomethicone, dimethicone,dimethicone cross-polymer, polysiloxanes and their derivatives,preferably organomodified derivatives including PDMS, dimethiconecopolyol, dimethiconols, and amodimethiconols; hydrocarbon oils such asmineral oil, petrolatum, isoeicosane and polyolefins, e.g.,(hydrogenated) polyisobutene; polyols such as propylene glycol,glycerin, butylene glycol, pentylene glycol, hexylene glycol, caprylylglycol; waxes such as beeswax, carnauba, ozokerite, microcrystallinewax, polyethylene wax, and botanical waxes; or any combinations ormixtures of the foregoing. Aqueous vehicles may include one or moresolvents miscible with water, including lower alcohols, such as ethanol,isopropanol, and the like. The vehicle may comprise from about 50% toabout 99% by weight of the composition.

In one embodiment of the invention, the compositions may includeadditional skin actives, including but not limited to, retinoids,botanicals, keratolytic agents, desquamating agents, keratinocyteproliferation enhancers, collagenase inhibitors, elastase inhibitors,depigmenting agents, anti-inflammatory agents, steroids, anti-acneagents, antioxidants, and advanced glycation end-product (AGE)inhibitors, to name but a few. The amounts of these various ingredientsare those conventionally used in the cosmetic field to achieve theirintended purpose, and range individually or collectively typically fromabout 0.001 wt % to about 20 wt % by weight of the composition. Thenature of these ingredients and their amounts must be compatible withthe production and function of the compositions of the disclosure.

Exemplary anti-aging components include, without limitation, botanicals(e.g., Butea frondosa extract); phytol; phytonic acid; retinoids;hydroxy acids (including alpha-hydroxy acids and beta-hydroxy acids),salicylic acid and alkyl salicylates; exfoliating agents (e.g., glycolicacid, 3,6,9-trioxaundecanedioic acid, etc.), estrogen synthetasestimulating compounds (e.g., caffeine and derivatives); compoundscapable of inhibiting 5 alpha-reductase activity (e.g., linolenic acid,linoleic acid, finasteride, and mixtures thereof); and barrier functionenhancing agents (e.g., ceramides, glycerides, cholesterol and itsesters, alpha-hydroxy and omega-hydroxy fatty acids and esters thereof,etc.), to name a few.

Exemplary retinoids include, without limitation, retinoic acid (e.g.,all-trans, or 9-cis, or 13-cis), and derivatives thereof, retinaldehyde,retinol (Vitamin A) and esters thereof, such as retinyl palmitate,retinyl acetate and retinyl propionate, and salts thereof. Particularmention may be made of retinol. When present, the retinoids willtypically be included in amounts from about 0.0001% to about 5% byweight, more typically from about 0.01% to about 2.5% by weight, or fromabout 0.1% to about 1.0% by weight. Compositions according to thisembodiment will typically include an antioxidant such as ascorbic acidand/or BHT and/or a chelating agent such as EDTA or a salt thereof(e.g., disodium EDTA).

In another embodiment, the topical compositions of the present inventionmay also include one or more of the following: a skin penetrationenhancer, an emollient, such as isopropyl myristate, petrolatum,volatile or non-volatile silicones oils (e.g., methicone, dimethicone),ester oils, mineral oils, and fatty acid esters; a humectant, such asglycerin, hexylene glycol or caprylyl glycol; a skin plumper, such aspalmitoyl oligopeptide, collagen, collagen and/or glycosaminoglycan(GAG) enhancing agents; a sunscreen, such as avobenzone or octylmethoxycinnamate; an exfoliating agent; and an antioxidant.

Suitable exfoliating agents include, for example, alpha-hydroxy acids,beta-hydroxy acids, oxa-acids, oxadiacids, and their derivatives such asesters, anhydrides and salts thereof. Suitable hydroxy acids include,for example, glycolic acid, lactic acid, malic acid, tartaric acid,citric acid, 2-hydroxyalkanoic acid, mandelic acid, salicylic acid andderivatives thereof. One exemplary exfoliating agent is glycolic acid.When present, the exfoliating agent may comprise from about 0.001% toabout 20% by weight of the composition.

Examples of antioxidants that may be used in the present compositionsinclude compounds having phenolic hydroxy functions, such as ascorbicacid and its derivatives/esters; beta-carotene; catechins; curcumin;ferulic acid derivatives (e.g., ethyl ferulate, sodium ferulate); gallicacid derivatives (e.g., propyl gallate); lycopene; reductic acid;rosmarinic acid; tannic acid; tetrahydrocurcumin; tocopherol and itsderivatives, including tocopheryl acetate; uric acid; or any mixturesthereof. Other suitable antioxidants are those that have one or morethiol functions (—SH), in either reduced or non-reduced form, such asglutathione, lipoic acid, thioglycolic acid, and other sulfhydrylcompounds. The antioxidant may be inorganic, such as bisulfites,metabisulfites, sulfites, or other inorganic salts and acids containingsulfur. Antioxidants may comprise, individually or collectively, fromabout 0.001% to about 10% (w/w), or from about 0.01% to about 5% (w/w)of the total weight of the composition.

Other additives include: vitamins, such as tocopherol and ascorbic acid;vitamin derivatives such as ascorbyl monopalmitate, tocopheryl acetate,and Vitamin E palmitate; thickeners such as hydroxyalkyl cellulose,carboxymethylcellulose, carbombers, and vegetable gums such as xanthangum; gelling agents, such as ester-terminated polyester amides;structuring agents; metal chelating agents such as EDTA or saltsthereof; pigments; colorants; and pH adjusters (citric acid,ethanolamine, sodium hydroxide, etc.). The composition may optionallycomprise other components known to those skilled in the art including,but not limited to, film formers, moisturizers, minerals, viscosityand/or rheology modifiers, anti-acne agents, insect repellents, skincooling compounds, skin protectants, lubricants, fragrances,preservatives, stabilizers, and mixtures thereof. In addition to theforegoing, the cosmetic compositions of the invention may contain anyother compound for the treatment of skin disorders.

In addition, the compositions contemplated by this disclosure caninclude one or more compatible cosmetically acceptable adjuvantscommonly used and known by the skilled practitioner, such as colorants,pearls, chromalites, micas, pigments, dyes, fragrances, emollients,humectants, preservatives, vitamins, chelators, thickeners, anesthetics,anti-allergenics, antifungals, antimicrobials, other anti-inflammatoryagents, antioxidants, antiseptics, depigmenting agents, film formers,insect repellents, pharmaceutical agents, photostabilizing agents,sunscreens, stabilizers, surfactants, thickeners, viscosity modifiers,and botanicals. The topical compositions of the present disclosure mayalso include a skin penetration enhancer, a surface smoother, a skinplumper, an optical diffuser, an exfoliation promoter, and anantioxidant. Details with respect to these and other suitable cosmeticingredients can be found in the “International Cosmetic IngredientDictionary and Handbook,” 10th Edition (2004), published by theCosmetic, Toiletry, and Fragrance Association (CTFA), at pp. 2177-2299,which is herein incorporated by reference in its entirety. The amountsof these various substances are those that are conventionally used inthe cosmetic or pharmaceutical fields, for example, they can constitutefrom about 0.01% to about 20% of the total weight of the composition.

A sunscreen may be included to protect the skin from damagingultraviolet rays. In an illustrative embodiment of the presentdisclosure, the sunscreen provides both UVA and UVB protection, by usingeither a single sunscreen or a combination of sunscreens. Among thesunscreens that can be employed in the present compositions areavobenzone, cinnamic acid derivatives (such as octylmethoxy cinnamate),octyl salicylate, oxybenzone, octocrylene, titanium dioxide, zinc oxide,or any mixtures thereof. The sunscreen may be present from about 1 wt %to about 30 wt % of the total weight of the composition.

In one embodiment, the topical composition will have a pH range from 1to 13, with a pH in the range of from 2 to 12 being typical. In someembodiment, the composition will have a pH in the range of from 3.5 to 7or from 7-10.5. In some embodiments, the pH will be in the range of 3-4,or 4-5, or 5-6, or 6-7, or 7-8, or 8-9, or 9-10, or 10-11, or 11-12.Suitable pH adjusters such as sodium hydroxide, citric acid andtriethanolamine may be added to bring the pH within the desired range.

Another embodiment of the present disclosure is directed to the deliveryof the described compositions by the use of targeted delivery systems,for example, liposomes, microspheres (see, e.g., U.S. Pat. No. 5,770,222to Unger et al.), and the like, so that the components and/or activeconstituents can more readily reach and affect the subcutaneous layer ofthe area of application, e.g., face or neck, or the other area of theskin.

The compositions may be formulated in a variety of product forms, suchas, for example, a lotion, cream, serum, spray, aerosol, cake, ointment,essence, gel, paste, patch, pencil, towelette, mask, stick, foam,elixir, concentrate, and the like, particularly for topicaladministration. Preferably the composition is formulated as a lotion,cream, ointment, or gel.

In certain embodiments, the cosmetic compositions described herein canbe used to treat and/or prevent hyper-pigmentation of skin and/or of thehair, for example, to lighten skin or hair. In some embodiments, acomposition is topically applied to the skin or hair, for example to anarea of hyper-pigmented skin or hair. Hyper-pigmentation includes anycoloration of an individual's skin or hair that is darker than desiredby the individual and that is caused by melanocytes. Such unwantedpigmentation may also be called discoloration. Hyper-pigmented areas ofthe skin include areas of discrete or mottled hyper-pigmentation. Areasof discrete hyper-pigmentation can be distinct, uniform areas of darkercolor and may appear as brown spots or freckles on the skin, includingmarks commonly called pigment spots or “age spots.” Areas of mottledhyper-pigmentation of the skin can be dark blotches that are larger andmore irregular in size and shape than areas of discrete pigmentation.Areas of hyper-pigmentation also include areas of tanned skin, forexample, skin tanned due to UV exposure. Hyper-pigmented hair includesany shade of hair that is darker than desired.

Treating hyper-pigmentation or hyper-pigmented skin/hair refers toeradicating, reducing, ameliorating, or reversing one or more of theunwanted features associated with hyper-pigmentation, such as producinga perceptible lightening of the skin or hair in the affected area.Lightening hyper-pigmented areas of the skin may be desirable, in oneembodiment, in diminishing age spots; lightening a suntan; evening oroptimizing skin tones, e.g., in areas of mottled hyper-pigmentation; intreating melasmic and chloasmic patches, freckles, after-burn scars, andpost-injury hyper-pigmentation. Preventing hyper-pigmentation orhyper-pigmented skin refers to affording skin, not yet affected byhyper-pigmentation, a benefit that serves to avoid, delay, forestall, orminimize one or more unwanted features associated with skinhyper-pigmentation, such as reducing the darkness or size ofhyper-pigmented areas that eventually develop.

Topical compositions comprising a compound (I) or (II) may be appliedfor a time sufficient to achieve a reduction in pigmentation in the areaof application. This may entail topical application at least once dailyfor at least one week, at least two weeks, at least four weeks, or atleast eight weeks or more. In some embodiments, the compositions areapplied directly to a site of hyperpigmentation on the skin (i.e.,directly onto an age spot or sun spot). In some embodiments, thecompositions are applied daily to achieve and/or maintain a reduction inpigmentation in the skin. In one embodiment, the compositions of theinvention will be applied to the skin in an amount from about 0.001 toabout 100 mg/cm², more typically from about 0.01 to about 20 mg/cm², orfrom about 0.1 to about 10 mg/cm².

The present inventive compositions provide for products, especially skincare and cosmetic products that lighten skin in need thereof. Skin inneed thereof includes, but is not limited to, dark complexions,hyperpigmented skin, post-inflammation hyperpigmented skin, age spots,liver spots, discolored or uneven skin, dark circles under the eyes forexample, skin having melasma, cholasma, freckles, after-burn scars,post-injury hyperpigmented skin, skin, scalp, legs, face, and otherareas where whitening or color reduction are desired, yellowed skin,stained nails, and the like.

One embodiment of the invention relates to methods of applying aneffective amount of the lightening composition described herein, tolighten an affected area of the skin as used herein. The lighteningcomposition may remain on the affected area in need of lightening or maybe rinsed off or otherwise removed depending on the application. Inorder to maintain the desired lightening effect, the protocol should becontinued for as long as the lightening effect is desired. Once theapplication of the lightening composition is discontinued, the desiredlightening effect may also diminish.

In another aspect of the invention, the compositions are appliedtopically to improve the aesthetic appearance of human skin. The methodcomprises topically applying to an area of the skin in need thereof acomposition comprising an effective amount of a compound of Formula (I)or (II) for a time sufficient to improve the aesthetic appearance ofsaid human skin. The compositions are topically applied to the skin ineffective amounts, by which is meant an amount sufficient to achieve ameasurable improvement in skin health or reduction in one or moredermatological signs of aging with daily (once, twice, etc.)administration, typically for a period of at least one week or more.

The aesthetic improvement of human skin may be an improvement of anyattribute or characteristic of skin, including without limitation:

(a) treatment, reduction, and/or prevention of fine lines or wrinkles;

(b) reduction of skin pore size;

(c) improvement in skin thickness, plumpness, and/or tautness;

(d) improvement in skin smoothness, suppleness and/or softness;

(e) improvement in skin tone, radiance, and/or clarity;

(f) improvement in procollagen, and/or collagen production;

(g) improvement in maintenance and remodeling of elastin;

(h) improvement in skin texture and/or promotion of retexturization;

(i) improvement in skin barrier repair and/or function;

(j) improvement in appearance of skin contours;

(k) restoration of skin luster and/or brightness;

(l) replenishment of essential nutrients and/or constituents in theskin;

(m) improvement of skin appearance decreased by aging and/or menopause;

(n) improvement in skin moisturization;

(o) increase in skin elasticity and/or resiliency;

(p) treatment, reduction, and/or prevention of skin sagging;

(q) improvement in skin firmness; and

(r) reduction of pigment spots and/or mottled skin; and

(s) improvement of optical properties of skin by light diffraction orreflection.

In a related implementation, a method is provided for the treatment ofwrinkles and/or fine lines on the skin human skin (typically, skin ofthe face) comprising topically applying to an area of the skin in needthereof (e.g., applying to a wrinkle or fine line) a composition ofFormula (I) or (II), for a time sufficient to improve the aestheticappearance of said human skin. The treatment may be a least once ortwice daily and may last for a period of at least four weeks, typicallyat least eight weeks or longer. The composition may optionally furthercomprise a retinoid (e.g., retinol or retinyl palmitate) and/or analpha-hydroxy acid (e.g., glycolic acid) and/or a beta-hydroxy acid(e.g., salicylic acid or derivative) in amounts effective to improve theappearance of skin.

In a related aspect, methods are provided for enhancing the productionof collagen or pro-collagen in human skin comprising topically applyingto an area of the skin in need thereof (e.g., sagging skin, thinningskin, skin suffering from wrinkles and fine line, etc.) a topicalcomposition comprising a cosmetically acceptable vehicle, and aneffective amount of a compound of Formula (I) or (II), for a timesufficient to improve the appearance thereof. The treatment may be aleast once or twice daily and may last for a period of at least fourweeks, typically at least eight weeks or longer. The composition mayoptionally further comprise a retinoid and/or an alpha-hydroxy acid(e.g., glycolic acid) and/or a beta-hydroxy acid (e.g., salicylic acidor a derivative) in amounts effective to improve the appearance of skin.

In yet another aspect of the invention, methods are provided forreducing the severity of, reducing the number of, or preventing orforestalling the onset of, wrinkles or fine lines on human skincomprising topically applying to an area of the skin in need thereof(e.g., wrinkled skin), an effective amount (e.g., 0.0001%-1% by weight,w/w) of a compound of Formula (I) or (II), in combination with aneffective amount (e.g., 0.01%-5% by weight, w/w) of retinol and/or aneffective amount (e.g., 0.001%-5% by weight, w/w) of an alpha-hydroxyacid (e.g., glycolic acid) and/or a beta-hydroxy acid (e.g., salicylicacid).

The invention provides a method for treating aging skin by topicallyapplying a composition comprising a collagen-stimulating compound ofFormula (I) or (II), typically in a cosmetically acceptable vehicle,over the affected area for a period of time sufficient to remediate,reverse, reduce, ameliorate, or prevent dermatological signs of aging.Generally, the improvement in the condition and/or aesthetic appearanceis selected from the group consisting of: reducing dermatological signsof chronological aging, photo-aging, hormonal aging, and/or actinicaging; preventing and/or reducing the appearance of lines and/orwrinkles; reducing the noticeability of facial lines and wrinkles,facial wrinkles on the cheeks, forehead, perpendicular wrinkles betweenthe eyes, horizontal wrinkles above the eyes, and around the mouth,marionette lines, and particularly deep wrinkles or creases; improvingthe appearance of suborbital lines and/or periorbital lines; reducingthe appearance of crow's feet; rejuvenating and/or revitalizing skin,particularly aging skin; reducing skin fragility; preventing and/orreversing of loss of glycosaminoglycans and/or collagen; amelioratingthe effects of estrogen imbalance; preventing skin atrophy; preventing,reducing, and/or treating hyperpigmentation or hypopigmentation;minimizing skin discoloration; improving skin tone, radiance, clarityand/or tautness; preventing, reducing, and/or ameliorating skin sagging;improving skin firmness, plumpness, suppleness and/or softness;improving procollagen and/or collagen production; improving skin textureand/or promoting retexturization; improving skin barrier repair and/orfunction; improving the appearance of skin contours; restoring skinluster and/or brightness; minimizing dermatological signs of fatigueand/or stress; resisting environmental stress; replenishing ingredientsin the skin decreased by aging and/or menopause; improving communicationamong skin cells; increasing cell proliferation and/or multiplication;increasing skin cell metabolism decreased by aging and/or menopause;retarding cellular aging; improving skin moisturization; enhancing skinthickness; slowing or halting skin thinning; increasing skin elasticityand/or resiliency; enhancing exfoliation; improving microcirculation;decreasing and/or preventing cellulite formation; and any combinationsthereof. In some embodiments, each of the forgoing is associated withfemale skin.

In some embodiments, the compounds of Formulas (I) or (II) will be usedto reduce the severity of fine lines or wrinkles, often in combinationwith retinol. The composition will typically be applied to the skin one,two, or three times daily for as long as is necessary to achieve desiredresults. The treatment regimen may comprise daily application for atleast one week, at least two weeks, at least four weeks, at least eightweeks, or at least twelve weeks or more. Chronic treatment regimens arealso contemplated. The effect of a composition on the formation orappearance of fine lines and wrinkles can be evaluated qualitatively,e.g., by visual inspection, or quantitatively, e.g., by microscopic orcomputer assisted measurements of wrinkle morphology (e.g., the number,depth, length, area, volume and/or width of wrinkles per unit area ofskin). In one embodiment, the cosmetic compositions of the inventionwill be applied to the skin in an amount from about 0.001 to about 100mg/cm², more typically from about 0.01 to about 20 mg/cm², or from about0.1 to about 10 mg/cm².

It is also contemplated that the compositions of the invention will beuseful for treating thin skin by topically applying the composition tothin skin of an individual in need thereof. “Thin skin” is intended toinclude skin that is thinned due to chronological aging, menopause, orphoto-damage and skin that is thinning prematurely. In some embodiments,the treatment is for thin skin in men, whereas other embodiments treatthin skin in women, pre-menopausal or post-menopausal, as it is believedthat skin thins differently with age in men and women, and in particularin women at different stages of life.

The method of the invention may be employed prophylactically toforestall aging including in individuals that have not manifested signsof skin aging, most commonly in individuals under 25 years of age. Themethod may also reverse or treat signs of aging once manifested as iscommon in individuals over 25 years of age, or to slow the progressionof dermatological aging in such individuals.

In one embodiment, the compositions of the invention are applied tohuman skin to reduce sebum production or improve the appearance of skinaffected by cellulite, and/or reduce unwanted lipogenesis or increaselipolysis. In this embodiment, the compounds of Formulas (I) or (II) canbe formulated in cosmetically acceptable vehicles (as described herein)and may include one or more additional agents such as anti-acneingredients (e.g., salicylic acid, benzoyl peroxide and other peroxides,sulfur, retinoids, etc.) in the case of a facial composition, or, in thecase of a cellulite treatment, the formulation may comprise anyingredients suitable for treatment of cellulite, including withoutlimitation, perilla oil and other unsaturated fatty oils and omega-3fatty acids such as alpha-linolenic acid; caffeine; theophylline;xanthines, retinoids (e.g., retinol); and the like. A cellulitetreatment according to the invention will typically be applied topicallyto skin suffering from cellulite, including skin of the buttocks andthighs for a period of time sufficient to improve the appearancethereof, including for example, daily treatment for at least four weeks,at least eight weeks, at least twelve weeks, or longer. In oneembodiment, the compositions are topically applied to treat acne.

In another embodiment, the compounds of Formulas (I) or (II) areintended for oral use, including for pharmaceutical use. Pharmaceuticalformulations will include pharmaceutically acceptable carriers (i.e.,diluents and excipients). The pharmaceutical compositions may beincluded in solid dosage forms, including compressed tablets andcapsules, or in liquid or powder forms. Pharmaceutical dosage forms willtypically include from about 0.5 mg to about 200 mg, or from about 1 mgto about 100 mg of the compound of Formulas (I) or (II). The dosageforms may be immediate release, in which case they will typicallycomprise a water-soluble or dispersible carrier such as microcrystallinecellulose, mannitol, hydroxypropyl methyl cellulose, PVP or the like, ormay be delayed, sustained, or modified release, in which case they maycomprise water-insoluble polymers such as cellulose ethers (e.g.,ethylcellulose), alone or in combination with water soluble ordispersible polymers, to regulate the rate of dissolution of the dosageform in the stomach.

In one embodiment, the composition is intended for use as anon-therapeutic treatment. In another embodiment, the composition is anarticle intended to be rubbed, poured, sprinkled, or sprayed on,introduced into, or otherwise applied to the human body for cleansing,beautifying, promoting attractiveness, or altering the appearance, inaccordance with the US FD&C Act, §201(i).

EXAMPLES

The following example illustrates a specific aspect of the instantdescription. The example should not be construed as limiting, as theexample merely provides specific understanding and practice of theembodiments and its various aspects.

Example 1

The Compound of Formula (II) was examined for its ability to reducepigmentation in vitro in human melanocytes. Human epidermal melanocytesfrom dark-pigmented skin were seeded in 6-well dishes and grown usingcommercially available Medium 254, a sterile, liquid medium preparedwith 200 μM calcium chloride for the culture of human epidermalmelanocytes, supplemented with 1% Penicillin/Streptomycin and 1% HumanMelanocyte Growth Supplement, Histamine, Diphenhydramine HCl andCompound II were added to the growth medium at the concentrations listedin Table 1 below. Corresponding controls were maintained withouthistamine, Diphenylhydramine HCl and Compound II. Four replicates weretested for each combination. After 8 days of incubation, melanin wascollected and processed by washing the wells with 1× phosphate-bufferedsaline (PBS), followed by addition of 200 μL of 2M NaOH to three of thefour replicates, which are then scraped, pooled and boiled at 80° C. foran hour. Melanin absorption was then measured at 405 nm using aspectrophotometer.

Results are summarized in Table 1 below as percent change of melaninabsorbance relative to vehicle control. A larger (positive or negative)percent change indicates a larger increase or reduction in melanin.

TABLE 1 Compound Concentration % Pigmentation Histamine 5 μM 58.75%Diphenhydramine HCl 5 μM −38.75% Compound (II) 0.001% −40.83% 0.0001%−10.40%

As shown in Table 1, histamine produces a significant increase inpigmentation whereas the histamine antagonist diphenhydraminehydrochloride reduces pigmentation. At both concentrations tested, thecompound of Formula (II) was effective to reduce pigmentation.

As various changes can be made in the above-described subject matterwithout departing from the scope and spirit of the present invention, itis intended that all subject matter contained in the above description,or defined in the appended claims, be interpreted as descriptive andillustrative of the present invention. Many modifications and variationsof the present invention are possible in light of the above teachings.Accordingly, the present description is intended to embrace all suchalternatives, modifications, and variances which fall within the scopeof the appended claims.

1. A topical composition comprising, in a topically acceptable vehicle,an effective amount of a compound having the structure of formula (I):

wherein, R^(N) are independently selected at each occurrence fromhydrogen or C₁₋C₁₂ hydrocarbons, optionally containing from 1-8heteroatoms selected from halogen, O, N, and S and combinations thereof;and wherein two groups R^(N) on the same nitrogen atom may together forma three- to six-membered ring; R^(a) is independently selected fromhydrogen, —F; —Cl; —Br; —I; —OH, —OR*; —NH₂; —NHR*; —N(R*)₂; —N(R*)₃ ⁺;—N(R*)—OH; —N(→O)(R*)₂; —O—N(R*)₂; —N(R*)—O—R*; —N(R*)—N(R*)₂; —C═N—R*;—N═C(R*)₂; —C═N—N(R*)₂; —C(═NR*)—N(R*)₂; —SH; —SR*; —CN; —NC; —(C═O)—R*;—CHO; —CO₂H; —CO₂ ⁻; —CO₂R*; —(C═O)—S—R*; —O—(C═O)—H; —O—(C═O)—R*;—S—(C═O)—R*; —(C═O)—NH₂; —(C═O)—N(R*)₂; —(C═O)—NHNH₂; —O—(C═O)—NHNH₂;—(C═S)—NH₂; —(C═S)—N(R*)₂; —N(R*)—CHO; —N(R*)—(C═O)—R*; —(C═NR)—O—R*;—O—(C═NR*)—R*, —SCN; —NCS; —NSO; —SSR*; —N(R*)—C(═O)—N(R*)₂;—N(R*)—C(═S)—N(R*)₂; —SO₂—R*; —O—S(═O)₂—R*; —S(═O)₂—OR*; —N(R*)—SO₂—R*;—SO₂—N(R*)₂; —O—SO₃ ⁻; —O—S(═O)₂—OR*; —O—S(═O)—OR*; —O—S(═O)—R*;—S(═O)—OR*; —S(═O)—R*; —NO; —NO₂; —NO₃; —O—NO; —O—NO₂; —N₃; —N₂—R*;—N(C₂H₄); —Si(R*)₃; —CF₃; —O—CF₃; —PR*₂; —O—P(═O)(OR*)₂; —P(═O)(OR*)₂;C₁-C₈ perfluoroalkyl; an aliphatic C₁-C₈ hydrocarbon radical; a C₁-C₈aromatic hydrocarbon radical; or a C₁-C₈ heteroaryl radical; X₁ and X₂are independently selected from oxygen, sulfur, NR^(N), or CR*R*; R* isindependently at each occurrence hydrogen or a straight chained,branched, or cyclic C₁-C₂₀ hydrocarbon radical, optionally substitutedwith one or more groups R^(a) or with 1-6 heteroatoms selected fromnitrogen, oxygen, sulfur, or halogen and combinations thereof; ring “A”is a five or six-membered optionally aromatic ring, z₁ is —C—, —N—,—NL₁-, or —CL₁-; and z₂-z₆ are independently selected from —N—, —NH—,—NR*—, —O—, —S—, —CH—, —CR—, —CR*—, and in the case where ring “A” is afive membered ring, z₄ is a bond (i.e., it is absent); where L₁ is group—X^(a)—(CH₂)_(r)—(CH═CH)_(s)—X^(b)—(CH₂)_(y)—(CH═CH)_(z)—X^(c)—, whereX^(a), X^(b), and X^(c) are independently a bond (i.e., absent), —O—,—S—, —NH—, —NR*— and “r,” “s,” “y,” and “z” are independently at eachoccurrence integers from 0-2; Z is selected from R*, OH, OR*, orNR^(N)R^(N), wherein R^(N) and R* are as defined above; and n and m areindependently integers from 0-6; and topically acceptable salts thereof.2. The composition according to claim 1, wherein said topicallyacceptable vehicle comprises a water-in-oil, oil-in-water,silicone-in-water, or water-in-silicone emulsion and further comprisesan emulsifier.
 3. The composition according to claim 1, wherein saideffective amount is from about 0.0001% to about 5% by weight based onthe total weight of the composition.
 4. The composition according toclaim 1, further comprising a retinoid in an amount from about 0.001% toabout 5% by weight based on the total weight of the composition.
 5. Thecomposition according to claim 1, further comprising at least one otheringredient selected from a film forming polymer, a thickener, a pHadjuster, a preservative, an emulsifier, a gelling agent, anantioxidant, an emollient, a humectant, a fragrance, and a colorant. 6.The composition according to claim 1, further comprising at least oneother depigmenting agent selected from nicotinamide,3,3′-thiodipropanoic acid, dilauryl thiodipropionate, Kojic acid,hydroquinone, salicylic acid, and resorcinol.
 7. A topical compositioncomprising, in a topically acceptable vehicle, an effective amount of acompound having the structure of formula (II):

and cosmetically acceptable salts thereof.
 8. The composition accordingto claim 7, wherein said topically acceptable vehicle comprises awater-in-oil, oil-in-water, silicone-in-water, or water-in-siliconeemulsion and further comprises an emulsifier.
 9. The compositionaccording to claim 7, wherein said effective amount is from about0.0001% to about 5% by weight based on the total weight of thecomposition.
 10. The composition according to claim 7, furthercomprising a retinoid in an amount from about 0.001% to about 5% byweight based on the total weight of the composition.
 11. The compositionaccording to claim 7, further comprising at least one other ingredientselected from a film forming polymer, a thickener, a pH adjuster, apreservative, an emulsifier, a gelling agent, an antioxidant, anemollient, a humectant, a fragrance, and a colorant.
 12. The compositionaccording to claim 7, further comprising at least one other depigmentingagent selected from nicotinamide, 3,3′-thiodipropanoic acid, dilaurylthiodipropionate, Kojic acid, hydroquinone, salicylic acid, andresorcinol. 13-18. (canceled)